1. Technical Field
The present invention relates to a hydraulic shock absorber and a cover member.
2. Related Art
Suspension devices for vehicles such as automobiles include a hydraulic shock absorber for appropriate dampening of vibration transmitted to the vehicle body from the road surface during the drive with the use of a damping force generator so as to improve the driving comfort and control stability. A hydraulic shock absorber includes a piston that is movably disposed inside a cylinder, for example, and divides the inside of the cylinder, a piston rod connected to the piston, and a fluid reserving chamber that compensates for volume changes of oil as the piston rod moves. A damping force is generated by giving resistance to the flow of fluid caused by the movement of the piston.
A triple tube shock absorber 908 is known (Japanese Translation of PCT Application No. 2007-506055), for example, which includes a pressure tube (first cylinder) 916, an intermediate tube 944, and a reserve tube 918, as shown in FIG. 10. This shock absorber 908 includes a rod guide (cover member) 936 that covers the pressure tube 916 at one end of the pressure tube 916 where the piston rod 914 protrudes, and that has a through hole for the piston rod 914 to extend through to support the piston rod 914 in contact therewith. A circumferential part of this rod guide 936 is apart from the pressure tube 916 to form a passage (opening) 956 that allows the fluid to flow from inside of the pressure tube 916 into a reserve chamber (fluid reserving chamber) 938 through an intermediate chamber 952.